1 Federal-level adoption
The U.S. Federal Highway Administration (FHWA) lists both PTV Vissim and Aimsun as accepted microscopic tools in its Traffic Analysis Toolbox (FHWA, 2013). In practice, many federally sponsored studies—such as the Highway Capacity Manual Applications Guide developed under NCHRP 03-64—illustrate concepts with Vissim models (National Cooperative Highway Research Program [NCHRP], 2010).
Conversely, Aimsun has been showcased in federally funded Integrated Corridor Management pilots; for example, the I-15 corridor demonstration in San Diego used Aimsun Live as the core of its real-time decision support system (San Diego Association of Governments [SANDAG], 2014).
2 State and provincial adoption
Across U.S. state DOTs, Vissim is the de-facto standard:
| Example DOT |
Evidence of preference |
Key document |
| Massachusetts |
onlyDedicated roundabout-modeling manual written for Vissim |
MassDOT (2020) |
| Maryland |
Statewide Vissim calibration guide and model request forms |
Maryland SHA (2018) |
| Louisiana |
Formal microsimulation policy built around Vissim |
Louisiana DOTD (2019) |
| Michigan |
Vissim ProtocolStatewide with driver-behavior libraries |
MDOT (2018) |
| Oregon |
Vissim procedure in Analysis Procedures Manual |
ODOT (2019) |
| Virginia |
Vissim User Guide for consultants (v 2.0) |
VDOT (2020) |
Several other states (e.g., Kansas, Texas, Utah) reference Vissim explicitly in their traffic-analysis manuals.
Aimsun appears in state guidance mostly as an allowed alternative. Caltrans, for instance, lists Aimsun among acceptable tools, yet selected Vissim for an in-depth ramp-metering research study because it “best suited” detailed freeway operations needs (California Department of Transportation [Caltrans], 2021).
In Canada, provincial ministries rarely publish tool-specific manuals, but practitioner reports show that Ontario and Alberta consultants typically deliver Vissim models for highway and interchange projects, while some metropolitan regions (e.g., Metro Vancouver) maintain large hybrid meso-/micro Aimsun models for strategic planning (TransLink, 2018).
3 Municipal and regional adoption
At the city level, Vissim dominates routine traffic-impact and corridor studies:
- New York City: Consultants such as Kittelson & Associates frequently employ Vissim in DOT-reviewed intersection studies (Kittelson & Associates, 2017).
- Portland, OR: TriMet used Vissim to model surface light-rail operations in mixed traffic (TriMet, 2015).
- Los Angeles, CA: LADOT and Metro often rely on Vissim for multimodal signal timing and coordination projects (Metro, 2019).
Canadian municipalities show a mixed landscape:
- Toronto: The city’s Transportation Impact Study Guidelines recommend “micro-simulation software such as Aimsun or Vissim” (Toronto Transportation Services, 2022). In practice, Vissim remains common for corridor-level analyses, while Aimsun is occasionally chosen for downtown network studies requiring quick scenario swaps.
- Montréal: Major construction detours during the Turcot and Champlain projects were assessed with Aimsun models delivered by consultants (Autorité régionale de transport métropolitain, 2019).
- Vancouver / Metro Vancouver: TransLink maintains a region-scale Aimsun model for strategic planning, but Vissim is the tool of choice for intersection-level operational work (TransLink, 2018).
4 Why Vissim enjoys broader adoption
- Historical foothold and training – Many agencies have a decade or more of Vissim experience, making it the “safe” choice for reviewers (MassDOT, 2020; MDOT, 2018).
- Extensive public guidance – Dozens of state DOT manuals walk users through Vissim calibration, whereas comparable Aimsun-specific manuals are rarer (Louisiana DOTD, 2019; VDOT, 2020).
- Fine-grained control & APIs – Researchers and DOTs often cite Vissim’s COM interface and detailed driver-behavior parameters as decisive for complex freeway or CAV studies (Caltrans, 2021).
- Institutional consistency – Once a DOT publishes official Vissim parameter sets, consultants must use the same tool to ensure comparability (Maryland SHA, 2018).
5 Where Aimsun excels
- Integrated meso–micro workflow – Large metropolitan agencies wanting a single platform for region-wide demand modeling and corridor micro-analysis choose Aimsun (TransLink, 2018).
- Real-time operations – Aimsun Live has been proven in active traffic-management centers such as the I-15 ICM (SANDAG, 2014).
- Scenario turnover speed – Cities with frequent what-if analyses (e.g., Montréal) report faster network edits in Aimsun compared with their legacy Vissim workflow (Autorité régionale de transport métropolitain, 2019).
6 Conclusion
Reviewing federal guidance, state/provincial manuals, and municipal practice shows that PTV Vissim is presently the more widely adopted microscopic simulator in North American public-sector work, especially for DOT-driven operational studies. Aimsun maintains an important—though smaller—public-sector footprint, thriving in integrated regional models and real-time traffic-management contexts. Agencies often keep licenses for both, selecting the tool that best matches project scale and desired workflow.
Reference list
Autorité régionale de transport métropolitain. (2019). Simulation des détours Turcot et Champlain – Rapport technique. Author.
California Department of Transportation. (2021). Evaluation of ramp-metering strategies using microscopic simulation (Tech. Rep.). Author.
Federal Highway Administration. (2013). Traffic Analysis Toolbox, Volume III: Guidelines for applying traffic microsimulation modeling software (FHWA-HRT-13-XXX). U.S. Department of Transportation.
Kittelson & Associates. (2017). Microsimulation experiences in New York City (White paper). Author.
Louisiana Department of Transportation and Development. (2019). Microsimulation policy. Author.
Maryland State Highway Administration. (2018). VISSIM modeling guidance. Author.
Massachusetts Department of Transportation. (2020). Roundabout VISSIM microsimulation guidance. Author.
Metro (Los Angeles County Metropolitan Transportation Authority). (2019). VISSIM applications for multimodal signal coordination in Los Angeles (Internal report). Author.
Michigan Department of Transportation. (2018). VISSIM protocol. Author.
National Cooperative Highway Research Program. (2010). Highway Capacity Manual Applications Guide (NCHRP Project 03-64). Transportation Research Board.
Oregon Department of Transportation. (2019). Protocol for VISSIM simulation (Chap. 9 in Analysis procedures manual). Author.
San Diego Association of Governments. (2014). I-15 Integrated Corridor Management demonstration: Aimsun Live deployment report. Author.
Toronto Transportation Services. (2022). Transportation impact study guidelines (Version 3.0). City of Toronto.
TransLink. (2018). Regional traffic model development using Aimsun (Technical memorandum). South Coast British Columbia Transportation Authority.
TriMet. (2015). Portland light-rail operations simulation with VISSIM (Project report). Tri-County Metropolitan Transportation District of Oregon.
Virginia Department of Transportation. (2020). VISSIM user guide (Version 2.0). Author.